In the AD9148 datasheet there is the list of all VDD connections (AVDD33, CVDD18, IOVDD and DVDD18) with a typical and a maximal value.
Is the maximal value the absolute maximum power consumption of the supplies or is this in a specific context ?
The maximimum power consumption is for the particular mode specified
(NCO OFF, PLL DISABLED, AND INV SINCFILTER BYPASSED, 8 × Mode, f DAC = 800 MSPS, f INTERFACE = 200 MSPS
The part can dissipate much higher power with NCO on and Inv Sinc on. You may need to add a heat sink
if you try to use NCO and INVsinc at max data rate.